Background. Sudden visual loss is a common complaint with variable presentations among patients of different ages. Some patients describe their symptoms as a gradually descending gray-black curtain or as blurring, fogging, or dimming of vision. Symptoms usually last a few minutes but can persist for hours. Variation in frequency ranges from a single episode to many episodes per day; recurrences may continue for years but more frequently occur over seconds to hours. It does not necessarily have to be a complete loss of vision. It could be a partial loss of vision, or a blurring of the visual field. In other cases, the vision loss may appear as a gray splotch that blocks sight. Visual aura in migraine is the most common type of aura, often presenting as a fortification spectrum, a zigzag figure near the point of fixation that may gradually spread right or left and assume a laterally convex shape with an angulated scintillating edge leaving variable degrees of absolute or relative scotoma in its wake. Many different causes of sudden visual loss are recognized; however, the most common reason for painless sudden visual loss is ischemia. Ischemia, often via mechanical obstruction, can affect any aspect of the visual system. Those who develop ischemia of the eye often have other evidence of atherosclerotic disease, such as coronary artery disease and peripheral vascular disease, which increases their susceptibility to ischemic events in other parts of the body. Conclusions. Sudden vision loss is a common complaint in eye care practices. Often, such a situation requires urgent attention.